Vehicle sleeper compartment bunk bed ladder

ABSTRACT

The invention provides a stowable ladder mechanism for an overhead bed or upper berth in a bunk bed. A horizontal linear guide is vertically spaced above a horizontal support surface and associated with a bed or berth. The rungs of the ladder are supported between two vertical uprights, one of which is fixed at one end of the berth and the second of which is coupled to the horizontal linear guide and translates across the horizontal support surface along one side of the bed. The plurality of rungs include swing sections mounted on hinges which hang vertically when the translatable vertical upright is positioned adjacent to the fixed vertical upright. When the translatable upright is positioned away from the fixed upright, the swing sections are supported in a horizontal position.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention:

[0002] The present invention relates to sleeping compartments forvehicles, and more particularly to a stowable step ladder for suchcompartments which may be compacted for stowage.

[0003] 2. Description of the Problem:

[0004] Fold down overhead beds and bunkbeds are a common response to thedesire to provide sleeping accommodations in a compartment with limitedspace, such as found on railroad passenger trains and in long haultrucks. Ease of access to the upper berth or berths of a bunkbed, or toa fold down overhead bed, requires a ladder of some sort. Due toconstraints of space, access to the berths is typically limited to oneside of the berth and, for the convenience of the passenger, the ladderis preferably located along the same side of the bed, although in somecases steps and hand grips are built into cabinets located at one end ofthe berth. For the convenience of the lower berth occupant, and to savespace, where ladders are used, they are preferably stowable. Making theladder stowable is aided by making the ladder foldable or collapsible.

[0005] Volvo in its VN 770 series trucks provides a stowable ladderbased on a parallelogram mechanism. The design stows cleanly andtightly, but uses gravity to aid opening. This means that the device canopen for a tired user more quickly than expected or can fall open if apassenger loses his grip while the vehicle is moving. What is desired isa stowable ladder which can be opened with one hand, but which does notmake use of gravity to unfold.

SUMMARY OF THE INVENTION

[0006] According to the invention there is provided a stowable laddermechanism for an overhead bed or an upper berth of a bunk bed. Theladder rests on a horizontal support surface. A horizontal linear guideis vertically spaced above the horizontal support surface and associatedwith a bed or berth. The rungs of the ladder are supported between twovertical uprights, one of which is fixed at one end of the berth and thesecond of which is coupled to the horizontal linear guide and translatesacross the horizontal support surface along one side of the bed. Theplurality of rungs include swing sections mounted on hinges which hangvertically when the translatable vertical upright is positioned adjacentto the fixed vertical upright. When the translatable upright ispositioned away from the fixed upright, the swing sections are supportedin a horizontal position.

[0007] Two principal embodiments of the invention are taught In a firstembodiment, the swing sections of the rungs are anchored with respect tothe fixed upright, and are interconnected by a tether which is attachedto the free ends of the sections and, at one end of the tether, to thetranslatable upright. Lifting upwardly on the top one of swingingsections lifts all of the sections and pulls the translatable uprightaway from its stowed position. In the second described embodiment, theswing sections of the rungs are anchored on the translatable upright.Pulling the translating upright outwardly from its stowed positioncauses the swing sections of the rungs to ride upwardly on openings inthe fixed upright, through which the swing sections are positioned,until they are raised, supported in a horizontal position on the fixedupright.

[0008] Additional effects, features and advantages will be apparent inthe written description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The novel features believed characteristic of the invention areset forth in the appended claims. The invention itself however, as wellas a preferred mode of use, further objects and advantages thereof, willbest be understood by reference to the following detailed description ofan illustrative embodiment when read in conjunction with theaccompanying drawings, wherein:

[0010]FIG. 1 is a perspective view of a truck cab partially cutaway toshow a living compartment with a bunk bed and stowable ladder;

[0011]FIG. 2 is a plan view of a stowable ladder constructed inaccordance with the invention;

[0012]FIG. 3 is a perspective view of a rung in accordance with oneembodiment of the invention;

[0013]FIG. 4 is a plan view illustrating operation of the firstembodiment of the invention;

[0014]FIG. 5 is a perspective view of a rung in the second embodiment ofthe invention; and

[0015]FIG. 6 is a plan view illustrating operation of the secondembodiment.

[0016]FIG. 7 is a partial view of an alternative locking embodiment.

[0017]FIG. 7A is the first of four drawings demonstrating the deploymentof the alternative locking embodiment of FIG. 7.

[0018]FIG. 7B is the second of four drawings of the sequence beginningwith FIG. 7A.

[0019]FIG. 7C is the third of four drawings of the sequence beginningwith FIG. 7A.

[0020]FIG. 7D is the fourth of four drawings of the sequence beginningwith FIG. 7A.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring now to the figures, in FIG. 1 is depicted a truck 10having a cab 14 mounted on a pair of frame side rails 12 (passenger sideonly shown). Truck 10 is depicted as a cab over design, although theinvention is equally applicable to other configurations. Cab 14comprises four exterior sidewalls, including a front sidewall 60, adriver sidewall 50, a passenger sidewall 62 and an aft sidewall 17,which enclose an interior space 16. Interior space 16 is divided into anoperator area forward and a living area aft. The operator area includesa driver station 42 having access to a steering wheel 46 and aninstrument and control panel 48. The driver station 42 and passengerarea 44 are positioned to good views through windshield 50 and to benext to doors 52 and 54 for easy egress from the vehicle. Fixed exteriorladders 79 located near the doors help with getting in and out of thevehicle.

[0022] A bunkbed 19 comprising a lower berth 20 and an upper berth 22 islocated in the living area and occupies the rear most portion ofinterior space 16 against aft wall 17. One side of each of the berths issubstantially flush against the interior face of aft wall 17 and theopposite major side of the berths open out into the interior space 16. Afull height cabinet 28, resting on floor 18, is located at one end ofberths 20 and 22. A stowable ladder 24, constructed in accord witheither of the major embodiments of the present invention is locatedalong the exposed major sides of the berths. As described below, ladder24 opens up along a side rail 26 of upper berth 22.

[0023]FIG. 2 is a plan view of the bunkbed 19 and a fully deployedladder 24. Lower berth 20 rests on stowage compartments 30. Ladder 24opens to a position partially blocking access to the lower berth 20.Ladder 24 comprises a translatable vertical upright support leg 32 whichis supported by floor 18, riding over the floor on a roller 36. Upright32 is coupled into a horizontal guide 33 formed in side rail 26, whichkeeps the travel of the upright linear along the sides of the berths 20and 22. A second upright 34 is positioned on cabinets 28 adjacent theends of berths 20 and 22. Three rungs 35, 37 and 39 are supportedbetween uprights 32 and 34. Rungs 35, 37 and 39 include hinges 36, 38and 40, respectively, which allow a section of each rung to hangvertically when the ladder is collapsed for stowage. A second preferredembodiment of the invention is illustrated in the figure, however thedescription has so far been limited to features common to bothembodiments. The vertical uprights used for supporting the rungs of theladders are denoted by the numerals 32 and 34 for the second embodimentand 132 and 134 in the second embodiment. Rungs are similarlydifferentiated.

[0024]FIG. 3 illustrates in detail rung 135, in accordance with a firstembodiment of the invention. Translatable upright 132 is illustratedmoved to its stowed position, directly adjacent fixed upright 134. Rung135 (shown partially in phantom) extends from fixed upright 134 throughan opening 78 in upright 132. Rung 135 comprises two major sections, ananchor section 72 and a swing or hinged section 70, connected near anend of each section on a pivot axle 36. An anchor section 72 is rigidlymounted to fixed upright 134 and extends horizontally therefrom towardopening 78.

[0025] When upright 132 is positioned adjacent to upright 134, anchorsection 72 extends through opening 78 placing pivot axle 136, and swingsection 70 entirely on the far side of upright 132 relative to upright134. In this position, swing section 70 is unsupported and pivotsdownwardly on pivot axis 136 to a substantially vertical orientationparallel with translatable upright 132. The free or swinging end ofswing section 70 terminates in a flange 74, which is partially insertedadjacent into an opening 178 adjacent the upper lip of the opening.Opening 178 is positioned below opening 78 on upright 132 and isprovided for rung 137. When translatable upright 132 is positioned atits maximum extension away from upright 134, flange 74 catches againstupright 132 below the lower lip of opening 78. Flange 74, andcorresponding flanges on the remaining swing sections, limit the maximumtravel of translatable upright 132 away from the fixed upright 134. Inthe expanded state of ladder 24, the lower lip of opening 78 supportsthe bottom of swing section 70 in a horizontal position aligned onanchor section 72, for use as a ladder rung 135.

[0026] Rung 135 is the topmost of a plurality of rungs and serves as theanchor for one end of a tether or flexible strap 76, which connects theends of adjacent rungs. The function of tether 76 is better explainedwith reference to FIG. 4 where it may be seen that tether 76 is anchoredat one end to swing section 70 and at the opposite end to a point belowall of the remaining rungs and near the bottom of translatable upright132. By grasping and lifting swing section 70 in the direction indicatedby the arrow “A”, swing sections 170 and 270 are also lifted asindicated by the arrow marked “B”. By virtue of tether 76 beingconnected at one end to translatable upright 132, the upright is pulledoutwardly in the direction indicated by arrow “C”, moving on a roller 90mounted to the bottom of the upright and which rides on floor 18. At themaximum extent of the travel of upright 132, notch 88 in swing section170 catches the lower lip of opening 178, retaining the ladder 24 in itsexpanded state. After translatable upright 132 has passed pivot axis136, upriht 132 can be grasped and moved away from fixed upright 134.

[0027]FIG. 5 illustrates a second embodiment of the invention in whichrungs are anchored on translatable upright 32. One feature of the secondembodiment common to both embodiments, but not illustrated in detailabove, is the cooperation between the translatable upright 32 (or 132)on a berth siderail 26. A upwardly open C-shaped bracket 133 engages onlip of a channel 33 open in the side of berth side rail 26. Theengagement of bracket 133 with channel 33 keeps translatable upright 32close against rail 26. Coupling of upright 32 to berth side rail 26 canof course be accomplished in a number of different ways.

[0028] In the second embodiment, the anchor sections and the swingsections of the rungs are reversed, with the anchor sections beingmounted on the translatable upright 32 and the swing sections extendingaway from the anchor sections toward the fixed position upright 34. Rung35 is illustrated comprising an anchor section 472 mounted ontranslatable upright 32 oriented inwardly toward fixed upright 34. Swingsection 470 extends through an opening in fixed upright 34, which is ahollow tube. The opening comprises two parts, a first shorter opening578 through the face of upright 34 closer to upright 32 and a second,taller opening 580 on the face of upright 34 away from upright 34. Thesignificant difference between openings 578 and 580 is that the lowerlip of the latter opening is substantially below the lower lip for theformer opening. The difference in heights between the lower lips of thetwo openings 578 and 580 gives the swing arm 470 a mechanical advantagewhile translating upright 32 moves away from fixed upright 34. The uppersurface 511 of rung 35 may be grooved for traction purposes.

[0029] Swing section 470 terminates in a flange 474. Swing section 470hangs vertically adjacent to the fixed upright 34 when the ladder isfully stowed, in a manner similar to described for the first embodiment,with flange 474, disposed on the free end of the swing section,partially inserted into opening 582, near the upper lip of the opening.The embodiments differ in how the swing sections are brought to ahorizontal position. As illustrated in FIG. 6, movement of translatableupright 32 away (in the direction of arrow “D”) from fixed upright 34pulls swing section 470, and the other swing sections, through openings580 and 578, and brings the section toward a horizontal position(indicated by arrow “E”). As section 470 is pulled from the openings itslower surface first contacts the lower lip of opening 580. A rampportion 471 extends for part of the length of section 470 along itsbottom surface, so that as the bottom surface comes into contact withthe lower lip of opening 578, the bottom surface of the swing sectionremains in contact with, and supported on the lower lips of bothopenings through fixed upright 34. Swing arm 470 substantially overlapsanchor section 472 on the outside thereof to insure that the rung formedby the arm and anchor section do not buckle under weight at hinge pin36. A similar overlap can be seen in FIG. 3 in relation to the rungforming components of the first embodiment

[0030] A ramp 471 is providd along the bottom edges of section 470adjacent flange 474. Ramp 471 has a length approximately equal to thehorizontal spacing between openings 578 and 580, with the slope of ramp471 selected to account for the difference in the heights of the lowerlips of the two openings. Thus swing arm 470 rests horizontally onetranslating upright 32 is deployed at its maximum extension for use.

[0031] The invention provides a stowable ladder which is highly compactwhen stowed. The ladder is mechanically simple, and minimizes problemswith associated with accidental deployment during vehicle operation. Nolatch or strap is required to secure the ladder when stowed. Instead theweight of the ladder's own components, e.g. swing arms, keeps the ladderstowed. For the first embodiment, the strap interconnecting the swingarms also helps pull the translating vertical section outward to deploythe ladder. Compaction of the ladder for stowage is aided by spacingrungs vertically by a factor related to their length so that protrudingportions of the swing sections of the rungs fit into the openings forimmediately lower rungs when the ladder is stowed. For the strapassisted embodiment, the translating vertical section must pass thehinge point of the rungs in order to support the swing sectionhorizontally. In either embodiment the ladder can be extended orretracted by a user in the upper bunk.

[0032] The swing section of the upper bunk ladder may move about whilethe vehicle is in motion. This can potentially cause extra noise and bea general annoyance to a driver or passenger of the vehicle. The swingsection of the ladder can be immobilized. An alternative lockingembodiment to accomplish this is shown in FIGS. 7, and in a deployingsequence in FIGS. 7A to 7D. There is a translating vertical upright 632that is next to a fixed vertical brace 634 when in the stowed position.In this condition the swing section 670 of the horizontal ladder runghangs vertically and is braced by the fixed vertical brace 634. Theswing section has an overlap portion 666. The overlap portion 666 andthe remainder of the swing section 670 by being in contact with thefixed vertical brace 634 will prevent the swing section 670 fromrotating about the hinge 667 when the ladder 624 is in the compact orstowed state. The hinge 667 connects the fixed anchor section 672 to theswing section 670. The fixed anchor section 672 fits through a fixedvertical upright 665. As the ladder 624 is initially deployed, the swingsection 670 is initially vertical as shown in FIG. 7A. The fixed anchorsection 672 moves horizontally in direction 619 through a slot in thefixed vertical upright 665. As the swing section 672 comes into contactwith the fixed vertical upright 665, the swing section starts to rotateabout the hinge 667, as shown in FIG. 7B. The distance between thevertical support brace 634 and the fixed vertical upright 665 is suchthat it allows just enough room for the swing section 672 to clear. InFIG. 7C, the swing section 672 is nearly horizontal. The swing section672 is fully horizontal and locks up against the fixed vertical upright665.

[0033] While the invention is shown in only one of its forms, it is notthus limited but is susceptible to various changes and modificationswithout departing from the spirit and scope of the invention.

What is claimed is:
 1. A ladder mechanism comprising: a horizontalsurface; a horizontal linear guide vertically spaced above thehorizontal surface; a translating vertical member supported on thehorizontal surface and coupled to the horizontal linear guide to have alinear track on the horizontal surface; a vertical member positionedparallel to the translating member and located adjacent one end of thelinear track of the vertical translating member; and a plurality ofrungs including swing sections mounted on hinges to hang parallel to thevertical support when the translating vertical member is positioned atthe end of its track adjacent to vertical support and to assumepositions parallel to the horizontal surface when the translatingvertical member is moved to an opposite end of its track.
 2. A laddermechanism as set forth in claim 1, the plurality of rungs furthercomprising: an anchor section for each rung affixed to the verticalmember, with the hinged section being attached at one end to an end ofthe anchor section distal to the vertical member.
 3. A ladder mechanismas set forth in claim 2, further comprising: a plurality of openingsthrough the translating vertical member, each one of the openingscorresponding to a different one of the plurality of rungs, whichextends through its corresponding opening.
 4. A ladder mechanism as setforth in claim 3, further comprising: a tether connecting free ends ofthe hinged section and anchored at one end to the translating verticalmember; and a flange disposed at the free ends of the hinged sectionsfor restraining movement of the translating vertical member past thefree ends of the hinged sections.
 5. A ladder mechanism as set forth inclaim 1, an anchor section for each rung affixed to the translatingvertical member, with the hinged section being attached at one end to anend of the anchor section distal to the translating vertical member. 6.A ladder mechanism as set forth in claim 5, further comprising: aplurality of openings through the vertical member, each one of theplurality of openings corresponding to a different one of the pluralityof rungs, each of which extends through its corresponding opening.
 7. Abunkbed for a truck sleeper unit, comprising: a floor; a lower bed andan upper bed stacked on the lower bed; a side rail to the upper bed; afixed upright positioned at one end of the upper bed adjacent the siderail; a translating upright supported from below by the floor andcoupled to the side rail to move linearly along a side of the upper bedfrom a position adjacent the fixed upright to a position spaced from thefixed upright; and a plurality of rungs supported between the fixedupright and the translating upright when moved to the spaced positionfrom the fixed upright and which at least partially collapse when thefixed upright and the translating upright are adjacent one another.
 8. Abunkbed as set forth in claim 7, wherein each rung is segmented into ananchor section and a swing section, which depends from the anchorsection at one end by a hinge.
 9. A bunkbed as set forth in claim 8,wherein the anchor section of each of the plurality of rungs is mountedto be immobile with respect to the fixed upright and a tether connectsthe ends of the swing sections distal to the hinges and outside oftranslating upright relative to the fixed upright.
 10. A bunkbed as setforth in claim 9, wherein the tether is anchored at one end to thetranslating upright.
 11. A bunkbed as set forth in claim 10, wherein thetranslating upright comprises a plurality of openings corresponding toeach rung and through which the rungs project.
 12. A bunkbed as setforth in claim 8, wherein the anchor section of each rung is mounted onthe translating upright and oriented in direction toward the fixedupright.
 13. A bunkbed as set forth in claim 12, wherein there are aplurality of openings through the fixed upright and the rungs extendthrough the openings.
 14. A bunkbed as set forth in claim 13, whereinwhen the translating upright is positioned adjacent the fixed upright,the anchor segments extend through the opening and the swing sectionshang downwardly along side the fixed upright and when the translatingupright is positioned away from the fixed upright the anchor sectionsare extracted from the openings and the swing section are rotatedupwardly to an orientation parallel to the floor and supported adjacenttheir free ends by the fixed upright.
 15. A bunkbed as set forth inclaim 14, wherein the swing section terminate in flanges preventingtheir withdrawal from the openings in the fixed upright.
 16. A stowableladder mechanism for an overhead bed or upper berth of a bunk bed,comprising: a horizontal support surface; a horizontal linear guidevertically spaced above the horizontal support surface and associatedwith a bed or berth; a pair of vertical uprights, one of which is fixedat one end of the berth and the second of which is coupled to thehorizontal linear guide and is translatable across the horizontalsupport surface along one side of the bed or berth; and a plurality ofrungs, each including a swing section which hangs vertically when thetranslatable vertical upright is positioned adjacent to the fixedvertical upright and which is supported in a horizontal position betweenthe pair of uprights when the translatable upright is positioned awayfrom the fixed upright.
 17. A stowable ladder as set forth in claim 16,further comprising the swing sections of the rungs being anchored at oneend on the translatable upright whereby pulling the translating uprightoutwardly from its stowed position causes the swing sections of therungs to ride upwardly on openings in the fixed upright, through whichthe swing sections are positioned, until they are supported in thehorizontal position between the uprights.
 18. A stowable ladder as setforth in claim 16, further comprising: the swing sections of the rungsbeing anchored at one end with respect to the fixed upright; and atether attached to the free ends of the swing sections and, at one endof the tether, to the translatable upright; whereby lifting upwardly onthe top one of swing sections lifts all of the swing sections and pullsthe translatable upright away from its stowed position.
 19. A laddermechanism comprising: a horizontal surface; a horizontal linear guidevertically spaced above the horizontal surface; a translating verticalmember supported on the horizontal surface and coupled to the horizontallinear guide to have a linear track on the horizontal surface; avertical member positioned parallel to the translating member andlocated adjacent one end of the linear track of the vertical translatingmember; a plurality of rungs including swing sections mounted on hingesto hang parallel to the vertical support when the translating verticalmember is positioned at the end of its track adjacent to verticalsupport and to assume positions parallel to the horizontal surface whenthe translating vertical member is moved to an opposite end of itstrack; and said translating vertical member being adjacent to a fixedvertical brace when in a stowed position, and a swing section of one ofsaid ladder rungs hangs vertically and is braced by said fixed verticalbrace when stowed; said vertical hanging when stowed swing sectionhaving an overlap portion, and said overlap portion and a remainder ofsaid vertical hanging when stowed swing section being in contact withsaid fixed vertical brace when stowed preventing said vertical hangingwhen stowed swing section from rotating about a hinge between said swingsection and an fixed anchor section.
 20. The ladder mechanism as setforth in claim 19, comprising: said fixed anchor section fits through afixed vertical upright, and as said ladder is initially deployed, saidswing section is initially vertical; and as said ladder deploys saidfixed anchor section moves horizontally through a slot in said fixedvertical upright; with said swing section coming into contact with saidfixed vertical upright causing said swing section to rotate about saidhinge.
 21. The ladder mechanism as set forth in claim 20, wherein:spacing between said vertical support brace and said fixed verticalupright allows just enough room for the swing section to clear saidvertical support brace.